1. Field of the Invention
The invention relates to methods of bonding poly(vinylidene chloride) and more particularly relates to a method employing a polyamide hot-melt adhesive.
2. Brief Description of the Prior Art
The prior art is replete with descriptions of polyamide compositions having hot-melt adhesive properties and the methods of their preparation. Representative of the prior art adhesive compositions are those described in U.S. Pat. Nos. 3,377,303 and 3,444,026. The latter compositions comprise the reaction product of a dimer fatty acid and a wide variety of diamines. The compositions described are known to be adhesives for bonding vinyl based polymeric resins.
Polyamide compositions useful as hot-melt adhesives for adhering vinyl plastics are also disclosed in U.S. Pat. No. 3,847,875. The latter compositions are the reaction product of 1,8- or 1,9-heptadecane dicarboxylic acid and specific heterocyclic diamines such as piperazine.
In spite of the availability of a wide variety of polyamide hot-melt adhesives, there has remained a need for a satisfactory method of bonding poly(vinylidene chloride) resins. These particular resins are difficult to bond with hot melt adhesives because of their low melting point.
The present invention comprises the discovery that a certain class of polyamide hot-melt adhesive compositions may be used to effectively bond poly(vinylidene chloride) resins, with greater strength than is obtainable in bonding vinyl resins, such as poly(vinyl chloride).